"Tech Topics" takes the mystery out of the equipment designed to improve pump systems.
Variable speed systems can provide constant water pressure over a fairly broad range of flow rates by electronically changing the speed of the motor, as the demand changes, to keep the system pressure constant. The advantages to the end-users include the elimination of annoying pressure fluctuations in their homes and an increase of motor life by reducing the number of damaging on/off cycles. Additionally, these systems may allow the use of a smaller pressure tank if space is a problem. And finally, they may reduce the amount of electricity used by the pump because the pump motor will be running at a reduced speed much of the time. One of the affinity laws states, “The amount of energy consumed by a pump motor varies by the cube of its speed.”